On Thu, May 28, 2020 at 10:07:18PM +0300, Jarkko Sakkinen wrote: > On Thu, May 28, 2020 at 07:16:35PM +0200, Borislav Petkov wrote: > > Lemme reply to all mails with one. :-) > > And except those last two. Those are allocating a page from the EPC > > sections so I'd call them: > > > > sgx_try_alloc_page -> sgx_alloc_epc_page_section > > __sgx_try_alloc_page -> __sgx_alloc_epc_page_section > > > > former doing the loop, latter doing the per-section list games. > > sgx_alloc_epc_page_section() is a bit nasty and long name to use for > grabbing a page. And even the documentation spoke about grabbing before > this naming discussion. I think it is a great description what is going > on. Everytime I talk about the subject I talk about grabbing. > > Lets just say that your suggestion, I could not use in a conference > talk as a verb when I describe what is going on. That function > signature does not fit to my mouth :-) I would talk about > grabbing a page. "allocate an EPC page from the specified section" It also works if/when we add NUMA awareness, e.g. sgx_alloc_epc_page_node() means "allocate an EPC page from the specified node". Note that I'm not inventing these from scratch, simply stealing them from alloc_pages() and alloc_pages_node(). The section thing is unique to SGX, but the underlying concept is the same. > This how I refactored yesterday (is in my GIT tree already): > > /** > * sgx_grab_page() - Grab a free EPC page > * @owner: the owner of the EPC page > * @reclaim: reclaim pages if necessary > * > * Iterate through EPC sections and borrow a free EPC page to the caller. When a > * page is no longer needed it must be released with sgx_free_page(). If > * @reclaim is set to true, directly reclaim pages when we are out of pages. No > * mm's can be locked when @reclaim is set to true. > * > * Finally, wake up ksgxswapd when the number of pages goes below the watermark > * before returning back to the caller. > * > * Return: > * an EPC page, > * -errno on error > */ > > I also rewrote the kdoc. > > I do agree that sgx_try_grab_page() should be renamed as __sgx_grab_page(). FWIW, I really, really dislike "grab". The nomenclature for normal memory and pages uses "alloc" when taking a page off a free list, and "grab" when elevating the refcount. I don't understand the motivation for diverging from that. SGX is weird enough as is, using names that don't align with exist norms will only serve to further obfuscate the code.
